Rectangular cathode-ray-tube envelopes

ABSTRACT

A rectangular cathode-ray-tube envelope including a funnel member, component or part formed with sidewalls which flare outwardly from a circular small end of the member or component through a transition region of the member near the small end thereof to a substantially rectangular large end of the component or member. The sidewalls in the transition region of the funnel member or part deviate somewhat from their usual circular crosssectional configuration and are formed with cylindrically curved portions thereon so that cross sections taken in the transition region in planes lying parallel with the ends of the member have generally oblate configurations with substantially straight line opposed sides.

I United States Patent [72] Inventors Albert M. Gossie 2,782,953 2/1957 Koch et al 220/23 A Painted Post; 3,161,314 12/1964 Pfleeger et al. A. 220l2.1 A Lawrence B. Hausheer. Corning; both of, Primary Emminer D0nald F Norton pp No 222 Assistant Examiner-lames R. Garrett [22] Filed Sept 2 I969 Attorneys-Clarence R. Patty, Jr. and Charles W. Gregg {45] Patented July 6, 1971 [73] Assignee Corning Glass Works Corning, N.Y.

[54] RECTANGULAR CATHODE RAY TUBE ABSTRACT: A rectangular cathode-ray-tube envelope in- ENVELOPES cludmg a funnel member, component or part formed with 10 Claims, 7 Drawing Figs sidewalls WhlCh flare outwardly from a circular small end of the member or component through a transition region of the [52] Cl 220/24 A member near the small end thereof to a substantially rectangu- [51] lnt.Cl ..H0lj 61/30, |ar large end f the component member The sidewalls in 1/28 the transition region of the funnel member or part deviate [50] Field of Search 220/21 A, somewhat from their usua] circular cross sectiona] configura A tion and are formed with cylindrically curved portions thereon so that cross sections taken in the transition re ion in lanes [56] References Cned lying parallel with the ends of the member hive gerfierally UNITED STATES PATENTS oblate configurations with substantially straight line opposed 2,236,708 4/1941 Grimditch 220/2.1 A sides.

PATENTEU JUL slsn SHEET 1 BF 2 IN VENTORS. Albert M. Gossie F ig. Z

Lawrence B. Hausheer AGENT PATENTEU JUL elsm 3.691; 035

SHEET 2 [IF 2 INVENTORS. Albert M Gossie Lawrence B. Hausheer AGENT RECTANGULAR CATHODE-RAY-TUBE ENVELOPES BACKGROUND OF THE INVENTION Attempts are continuously being made to reduce the weight and also the length of rectangular cathode-ray-tube envelopes as measured along the longitudinal axis thereof from the center of the free end of the neck portion of the tube envelope to the center of the faceplate or viewing panel of the envelope. To aid in attaining such reductions in weight and length, the transition region between the circular small end of cathoderay-tube funnel members and the rectangular large end of such members have recently been formed with flares of increasingly wider electron beam deflection or clearance angles, such angles progressing to 110 and wider. Such bulbs are usually termed wide-angle bulbs in the glass making industry.

It has been found that rectangular cathode ray tube envelopes having funnel members or parts of the type set forth above are subject to a greater possibility of implosion originating in the aforementioned transition region of the funnel members or components either during the exhaust cycle of the tube envelopes in the manufacture of complete cathode ray tubes or during the handling of such tubes subsequent to such manufacture. Accordingly, the funnel members or components embodying the present invention were developed to reduce or minimize cathode ray tube implosions originating in the aforementioned transition region of the funnel members or components. The nature of the present invention will become apparent to those skilled in the art from the following detailed description taken in conjunction with the accompanying sheets of drawings which illustrate only the preferred example or embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1. is a side elevational view of a rectangular cathoderay-tube envelope having a funnel member formed in accordance with the present invention;

FIG. 2 is an end elevational view of a rectangular cathoderay-tube envelope having a funnel member formed in accordance with the invention; and FIGS. 3 through 7 are views of a funnel member embodying the invention, such views being taken generally along lines 33, 44, 5-5, 6-6 and 7-7, respectively, of FIG. 2.

Similar reference characters refer to similar parts in each of the FIGS. of the drawings.

PREFERRED EMBODIMENT OF THE INVENTION FIGS. 1 and 2 of the drawings, as previously mentioned, comprise side and end elevational views, respectively, of a funnel member embodying the invention and forming a portion of a rectangular cathode-ray-tube envelope 9. That is to say, FIGS. I and 2 are elevational views of a cathode-raytube envelope 9 including a funnel member 10 embodying the invention, such views illustrating the configuration or shape of the funnel member or funnel component when viewed along lines extending parallel with the major and minor axes, respectively, of the large end of funnel member 10, such axial designations being well known to those skilled in the art. Fun nel member 10 includes sidewalls which flare outwardly in the usual manner from a circular small end II of the member through a transition region 12 thereof near such small end 11 to a substantially or generally rectangular large end 13. Transition region 12 includes the region of the sidewalls of member 10 which extends approximately between lines 33 and 7-7 of FIG. 2.

For the purpose of accomplishing the object of the invention, that is, for the purpose of providing a strengthened rectangular cathode-ray-tube envelope, the sidewalls of funnel member 10 are provided with cylindrically curved portions 14 and 15 in the aforementioned transition region 12. Such cylindrically curved portions are preferably located in transition re gion 12 in alignment with the ends of the aforementioned minor axis of the generally rectangular large end of funnel member 10. That is to say, diametrically opposite portions 14 and 15 of the sidewalls of transition region 12 of funnel member or component 10 are formed so that such portions 14 and I5 curve, to any substantial extent, only in directions extending between said large end of the funnel member 10 and said small end thereof. Portions l4 and 15 are each preferably generally bisymmetrical or bilaterally symmetric on opposite sides of a centerline or axis for each respective portion, such centerlines or axes preferably being in alignment with the minor axis of the generally rectangular large end of funnel member 10. In FIG. 1 the profile of the transition region of a conventional rectangular cathode-ray-tube envelope funnel member or component as viewed in a direction extending parallel with the major axis of such funnel member is illustrated by the dotted lines 16 and 17 while the profile of the corresponding transition region of the funnel member 10 of the present invention is illustrated by the solid lines in said transition region illustrating the cylindrically curved portions 14 and. 15 on funnel member 10.

Referring to FIGS. 3 through 7, the generally bilaterally symmetric or bisymmetrical configurations or shapes of the cylindrically curved portions 14 and 15 on a funnel member or component such as 10 are illustrated so as to be readily understood by those skilled in the art. In each of the drawings FIGS. 3 through 7 a complete view of a funnel member such as 10 is not illustrated for purposes of simplification of the drawings, but a 'sufficient portion of member 10 is illustrated in each such drawing FIG. to enable those skilled in the art to readily understand the shape or configuration of such a funnel member 10 in transition region 12 of the member. It is pointed out, with reference to FIGS. 3 through 7, that the cylindrically curved portions 14 and 15 provided in transition region 12 on funnel member or component 10 are not provided by forming only areas of the outer surface of such funnel member in the transition region with cylindrically curved configurations or shapes but that portions 14 and 15 are provided by forming the entire thickness of the sidewall in portions 14 and 15 of the transition region with a cylindrically curved configuration. It is for the purpose of the previously mentioned electron-beam clearance or deflection angles that generally flat portions 14 and I5 are preferably located with the aforementioned centerlines or axes thereof in general alignment with the minor axis of the large end of a funnel member such as 10. By such location of portions 14 and 15 on funnel member 10 the deflection or clearance angles for the electron beams, during the operation of a cathode-ray tube having a funnel member formed in accordance with the present invention, will not be diminished or reduced below the electron beam clearance or deflection angles provided in the previously conventional so-called wideangle tubes.

While it is not completely certain why conventional wideangle cathode-ray-tube envelopes are subject to implosions thereof originating in the transition regions of the funnel members or components of such envelopes, measurements taken in such regions indicate that during and subsequent to the exhaustion of conventional wide-angle tubes in the manufacture of complete cathode-ray tubes that the large ends of the transition regions of the funnel members of the tube envelopes tend to increase in diameter on the minor axes of such ends and decrease in diameter on the major axes thereof. Such changes in diameter apparently apply axial bending tension in the smaller diameter sections of the transition regions of the funnel members of conventional cathode-ray-tube envelopes. This axial bending tension can cause implosions thereof originating in or near those areas of said smaller diameter sections which correspond in position or are aligned with the major axes of each respective funnel member. It has been found that by forming the transition regions of funnel mem bers or components as disclosed herein, that cathode-ray-tube envelopes incorporating such funnel members are strengthened so substantially as to obviate implosion of the tube envelopes originating in the aforesaid transition region of the funnel members. For example, conventional wide-angle tubes whose sidewalls were abraded on the outer surfaces of the transition region of the funnel components or members of such tubes and which were then subjected to increasing external fluid pressure imploded at an average pressure of 33 p.s.i. Similar wide-angle tubes incorporating funnel members or components formed in accordance with the present invention and subjected to the same treatment and tests imploded at an average pressure of 57 p.s.i. thereby indicating an increase in strength in excess of 50 percent. The purpose of abrading the aforementioned surfaces prior to said pressure tests is to attempt to duplicate conditions to which the cathode-ray tubes may be subjected during handling thereof.

While the invention disclosed herein has been described in detail in conjunction with so-called wide-angle cathode-ray tubes or tube envelopes having electron-beam deflection or clearance angles of approximately 110 or greater, it will be readily apparent to those skilled in the art that the invention may be advantageously applied to cathode ray tubes or tube envelopes having electron-beam deflection or clearance angles of somewhat less than 1 It is also pointed out that the invention disclosed may be used in the manufacture of one-piece cathode-ray-tube envelopes as well as cathode-ray-tube envelopes fabricated by separately forming faceplates or viewing panels, and funnel members or components, and then sealing pairs of such parts to each other in the manner well known in the art of cathoderay-tube manufacture.

We claim:

1. A funnel member for use in fabricating a rectangular cathode-ray-tube envelope, such funnel member including sidewalls which flare outwardly from a circular small end of the member through a transition region of the member near said small end thereof to a substantially rectangular large end of the member, said sidewalls in said transition region of said funnel member having cylindrically curved portions thereon such that cross sections taken in such transition region in planes extending parallel with said ends of the funnel member have generally oblate configurations with substantially straight line opposed sides.

2. A funnel member in accordance with claim 1 and in which the possible beam-deflection angle of the funnel member is approximately at least 1 10.

3. A funnel member as set forth in claim I and in which the common plane of the curved centerlines of said cylindrically curved portions of said sidewalls in said transition region is in general alignment with the minor axis of said rectangular large end of the funnel member.

4. A funnel member as set forth in claim 2 and in which the common plane of the curved centerlines of said cylindrically curved portions of said sidewalls in said transition region is in general alignment with the minor axis of said rectangular large end of the funnel member.

5. In a rectangular cathode-ray-tube envelope including a funnel component having sidewalls which flare outwardly from a circular small end of the component through a transition region thereof towards a substantially rectangular large end of the component, the improvement which comprises, diametrically opposite portions of said sidewalls in said transition region of the funnel component being so formed that such portions curve to any extent only in directions extending between said large end of the funnel component and said small end thereof, whereby said member is substantially strengthened in said transition region thereof.

6. A funnel component in accordance with claim 5 and in which the possible beam deflection angle of the funnel component is approximately at least 1 10.

7. A funnel component as set forth in claim 5 and in which the common plane of the curved centerlines of said diametrically opposite portions of said sidewalls is in alignment with the minor axis of said rectangular large end of the funnel component. I

8. A funnel component as set forth in claim 6 and in WhlCh the common plane of the curved centerlines of said diametrically opposite portions of said sidewalls is in alignment with the minor axis of said rectangular large end of the funnel component.

9. A funnel member for a cathode-ray-tube envelope, such funnel member comprising sidewalls which taper from a generally rectangular large end of the member through a transition region thereof to a generally circular small end of the member, the sidewalls in said transition region of the member having selected first and second opposite cylindrically curved areas each with its straight line elements extending in directions generally parallel with the major axis of said large end of the funnel member and with its curved line elements extending in directions generally aligned with the minor axis ofthe large end of the funnel member.

10. A funnel member in accordance with claim Q and in which the possible beam-deflection angle of the funnel member is approximately at least 1 10. 

1. A funnel member for use in fabricating a rectangular cathoderay-tube envelope, such funnel member including sidewalls which flare outwardly from a circular small end of the member through a transition region of the member near said small end thereof to a substantially rectangular large end of the member, said sidewalls in said transition region of said funnel member having cylindrically curved portions thereon such that cross sections taken in such transition region in planes extending parallel with said ends of the funnel member have generally oblate configurations with substantially straight line opposed sides.
 2. A funnel member in accordance with claim 1 and in which the possible beam-deflection angle of the funnel member is approximately at least 110*.
 3. A funnel member as set forth in claim 1 and in which the common plane of the curved centerlines of said cylindrically curved portions oF said sidewalls in said transition region is in general alignment with the minor axis of said rectangular large end of the funnel member.
 4. A funnel member as set forth in claim 2 and in which the common plane of the curved centerlines of said cylindrically curved portions of said sidewalls in said transition region is in general alignment with the minor axis of said rectangular large end of the funnel member.
 5. In a rectangular cathode-ray-tube envelope including a funnel component having sidewalls which flare outwardly from a circular small end of the component through a transition region thereof towards a substantially rectangular large end of the component, the improvement which comprises, diametrically opposite portions of said sidewalls in said transition region of the funnel component being so formed that such portions curve to any extent only in directions extending between said large end of the funnel component and said small end thereof, whereby said member is substantially strengthened in said transition region thereof.
 6. A funnel component in accordance with claim 5 and in which the possible beam deflection angle of the funnel component is approximately at least 110*.
 7. A funnel component as set forth in claim 5 and in which the common plane of the curved centerlines of said diametrically opposite portions of said sidewalls is in alignment with the minor axis of said rectangular large end of the funnel component.
 8. A funnel component as set forth in claim 6 and in which the common plane of the curved centerlines of said diametrically opposite portions of said sidewalls is in alignment with the minor axis of said rectangular large end of the funnel component.
 9. A funnel member for a cathode-ray-tube envelope, such funnel member comprising sidewalls which taper from a generally rectangular large end of the member through a transition region thereof to a generally circular small end of the member, the sidewalls in said transition region of the member having selected first and second opposite cylindrically curved areas each with its straight line elements extending in directions generally parallel with the major axis of said large end of the funnel member and with its curved line elements extending in directions generally aligned with the minor axis of the large end of the funnel member.
 10. A funnel member in accordance with claim 9 and in which the possible beam-deflection angle of the funnel member is approximately at least 110*. 